Photographic film developing composition containing beta, beta&#39;-di-chloroethyl ether



Patented Oct. 27, 1953 PHOTOGRAPHIC FILM DEVELOPING COM- POSITION CONTAINING BETA,BETA'-DI- CHLOROETHY L ETHER Leonard A. Robbins, Salt Lake City, Utah No Drawing. Application January 3, 1950, Serial No. 136,655

3 Claims.

This invention relates to compositions of mattor for use the development of photographic films, and particularly to aqueous solutions for the purpose.

In the art of developing photographic film, it is highly desirable that there be rapidity of reaction between the developing solution and the exposed film, a maximum of shadow detail (sometimes refererd to as emulsion speed), good contrast, reasonably fine grain, and long useful life of the solution.

In the past it has been impossible to attain all of the above in a single developing composition. For example, prior art developing solutions that are rapid, impart coarse grain and chemical fog, accompanied by softening of the emulsion. Furthermore, such rapid-action solutions have an abnormally short active life. On the other hand, prior art developing solutions which impart fine grain, as Well as protect the emulsion and inhibit chemical fog, are extremely slow in developing the film.

Thus, it has heretofore been necessary to sacrifice one or more of the specified desirable characteristics in order to attain the others. In other words a compromise, forfeiting one or more of such characteristics in order to achieve the others, has been necessary.

In photography as practiced under modern conditions, the attainment of maximum speed in developing negatives is not only desirable, but often imperative, as, for example, in the production of photographs for newspaper use, wherein time is short and deadlines are frequent. Furthermore, a composition having a long useful life is highly desirable in all instances, in order to eliminate the time and cost involved in fre- ;quent mixing of a fresh solution.

Among the principal objects of the invention, therefore, are:

To achieve maximum rapidity of processing in film development, while maintaining normal contrast and fine grain in the resulting negative;

To achieve maximum rapidity of processing while, at the same time, improving shadow detail;

To achieve maximum rapidity of processing, accompanied by long useful life of the developing composition;

To minimize possible damage to the emulsion surface during film development;

To condition the reaction between an inorganic alkaline agent and the film emulsion, thereby regulating the degree of softening of the emul- :s1on.

It is well known that strong inorganic alkaline agents, such as the alkaline metal hydroxides and, to a lesser degree, the carbonates, speed the action of film developing solutions. They do this, however, at the sacrifice of contrast and clearness in the resulting negative, which suffers from chemical fogging due to softening of and harsh reaction on the film emulsion.

I Some success in the use of such inorganic alkaline agents has been had in the past, especially in the case of the alkaline metal carbonates, phosphates, and metaborates, by the addition of an alkaline metal bromide to the solution. While this largely counteracts the harsh effects, the useful life of the solution is seriously shortened. Furthermore, grain structure is too coarse for best effect, and contrast is much greater than generally desirable.

In accordance with the present invention, I have found that the addition of a water soluble, aliphatic amine, especially and for example triethanolamine, to the developing solution, permits the use of such inorganic alkaline agents in the are often superior with respect to fine grain and contrast than are those produced by the use of conventional, slow-action developing compositions. Additionally, definite improvement in shadow detail is noticeable, and the developing solution has a long useful life.

I am aware of the fact that triethanolamine has been used heretofore in certain standard, slow-action developing solutions in place of alkalies normally used for the purpose of speeding development time. Nevertheless, this use of a water soluble, aliphatic amine, as a primary speed-imparting agent, difiers essentially from its use pursuant to this invention, where it serves as a modifier for the primary speed-imparting agent, namely, an inorganic alkali.

Thus, a well known and widely used developing solution, producing fine grain but being slow in its developing action, is made up as follows:

Grams Monomethyl para aminophenol sulfate 8 sodium sulfite 400 Hydroquinone 20 sodium tetraborate (borax) 8 Water to make one gallon of solution.

The use of triethanolaminein place of sodium tetraborate. (borax) in the above developing composition brings about a considerable reduction in processing time. Thirty (30) to sixty (60) cos. of triethanolamine per gallon results in cutting the processing time from approximately 16 minutes at 68 to approximately 6 minutes.

On the other hand, the addition of from thirty (30) to sixty (60) cos. of triethanolamine to the following faster standard developing solution containing the inorganic alkali, sodium carbonate, cuts the film processing time down from approximately 6 minutes at 68 F. to approximately 3 minutes. Furthermore, the useful life of the solution is greatly extended, and somewhat greater shadow detail is attained with normal contrast.

Grams Monomethyl para aminophenol sulfate 6 Sodium sulfite 72 Hydroquinone 10 Sodium carbonate '72 Potassium bromide 4 Water to make one gallon of solution.

phates or metaborates, may be employed. The

alkaline metal hydroxides, however, while operable, are not commercially desirable, due to their severe action and the relatively short life they impart to the developing solution.

Any of the organic developing agents commonly used in photography, such as amidol, pyrogallol, hydroquinone, chlorohydroquinone, toluhydroquinone, glycin, and catechol, may be employed in developing solutions conforming to this invention.

Relatively large amounts of sodium sulfite, as are customarily employed in fine grain developers, preserve the organic developing agents listed above and prevent undue softening of the film emulsion. However, as so used, sodium sulfite gradually oxidizes to sodium sulfate, which has no preservative action and actually slows down development by rendering the emulsion of the film less permeable to the action of the developing agents. Customary amounts of sodium sulfite as are currently used in fine grain developers, thus, lengthen developing time beyond the desired requirements of this invention. On the other hand, very small amounts do not properly preserve the organic developing agents from oxidation, nor prevent the emulsion of the film from becoming too soft.

An important aspect of the invention is the discovery that the addition to the solution of a water soluble, neutral, aliphatic, oxygenated, organic compound, for example an ether, alcohol, or ketone, and preferably a dichlorodiethyl ether compensates for a reduced amount of sodium sulfite, so far as protection of the film emulsion against softening is concerned. Accordingly, by reducing by approximately one-half the quantity of sodium sulfite customary in fine grain developers, and by adding a compensating quantity of the said organic compound, developing time is shortened and the film emulsion is protected.

This aspect of the invention is applicable to developing solutions generally, particularly the use of a dichloroethyl ether, but has its greatest importance in connection with the novel combination of an inorganic alkali and a water soluble, aliphatic amine herein disclosed. In this latter connection it should be noted that greater quantities of the inorganic alkali in the solution usually call for greater quantities of the oxygenated organic compound than would normally compensate for reduction of customary quantities of sodium sulfite.

The optimum range of sodium sulfite in developing solutions conforming to the invention is from 160 to 220 grams per gallon. However, more or less may be employed in particular instances.

While sodium sulfite is usually preferred, any of the alkali metal sulfites may be employed instead.

As stated hereinbefore, alkali metal bromides have in the past been used in developing solutions to modify the action of alkaline metal carbonates, phosphates, or metaborates, thereby greatly reducing the occurrence of chemical fog in the developed image. However, they also restrain development, especially in the weaker portions (shadow areas) of the negative, thus prolonging the time of development. Nevertheless, I have found that water soluble inorganic halides can be used to advantage in developing solutions of my invention, so long as care is exercised in the quantities employed.

Specific examples of water soluble inorganic halides found suitable are ammonium bromide, potassium bromide, sodium chloride, and potassium iodide. Because of superior results in practice, the bromides are preferred over the iodides and chlorides. Especially good quality negatives are obtained through use of compositions containing ammonium bromide.

I have found that, when an alkaline metal carbonate, phosphate, or metaborate, and a water soluble, aliphatic amine, such as triethanolamine, are used in combination with a water soluble, neutral, aliphatic, oxygenated organic compound, considerably less of the inorganic halide is required. In fact, the quantity is so small relatively speaking, that it is wise to strike a careful balance in the developing composition. Useful range of the bromide is from .25 to 10 grams, depending upon whether less or more of the oxygenated organic compound is utilized. A more preferred range is from 1 to 8 grams per gallon. A still more preferred range is from 125 to 6 grams per gallon. Optimum is from 1.5 to 3 grams per gallon.

In place of or in combination with the inorganic halide, benzotriazole can be used. If employed in place of an inorganic halide, it is added to the developing composition in the proportion of from approximately 1 to 3 grains per gallon of the solution.

Aliphatic amines particularly suitable for use in developing solutions of the invention include those which are soluble to at least 0.5 by weight in water. Oxygen-containing aliphatic amines form a preferred class, because of ease of handling and results obtained. Hydroxyalkylamines, particularly the beta hydroxyethylamines, form a still more preferred class, because of their low cost and effectiveness in low concentrations. Triethanolamine is particularly preferred, because of the outstanding results produced through its use. Other specific amines suitable for use include monoethanolamine, diethanolamine, N,N- diethyl-N-beta-hydroxyethylamine, N-butyl-N,N- bis (beta-hydroxyethyl) amine and triethylamine. Mixtures of two or more amines can be used. For example, technical triethanolamine, which contains appreciable quantities of monoand diethanolarnines, gives excellent results.

The quantity of aliphatic amine required in any specific instance depends upon the amount of inorganic alkali used, and varies with the specific amine. The more alkali utilized, the less amine. In general, from 0.05% to 8% by Weight, based on the particular composition of the developing solution, is useful. Little is gained through use of quantities above 4%, however. From 0.10% to 3% represents a preferred range, and. the most satisfactory all around results are obtained in the range of 0.20% to 1.5%.

From 40 to 240 grams, or more, of sodium carbonate can be used in combination with substantially inversely proportional quantities of triethanolamine, within the range heretofore specified for the latter, to give a solution which will permit the development of well balanced negatives in from 180 to 60 seconds or less at 68 F. It is preferable, however, to use from 60 to 180 grams of sodium carbonate per gallon, since there is little advantage in using more, and amounts significantly less than 60 grams results in longer developing time.

Better all around results are obtained with about 90 to 150 grams of sodium carbonate per gallon. Optimum results are realized however, when about 110 to 130 grams per gallon are used.

In place of sodium carbonate, there can be employed comparable quantities of other alkaline metal carbonates, such as potassium carbonate, or other inorganic agents of comparable alkalinity, such as the alkaline metal phosphates, and metaborates. Nevertheless, the inorganic alkaline carbonates are preferred for use in this developing composition, due to their availability and lower cost. Sodium carbonate is especially preferred.

The precise amount of any specific inorganic alkali for best results in any given developing composition, is easily determined by experiment. In general this will be from about 20 to 400 grams per gallon of the developing composition. In most cases the amount will vary from 50 to 200 grams per gallon.

For best all around results, it is essential to have what can be termed a balanced developing composition. For example, if a large amount of sodium carbonate, say 180 grams per gallon is employed, then it is desirable to use somewhat larger quantities of the water soluble, neutral, aliphatic oxygenated organic compound and inorganic bromide or the like than usual.

Halogen-containing anti-softening agents form a preferred class of the water soluble, neutral, aliphatic, oxygenated, organic compounds referred to hereinbefore, because of their ef fectiveness. Of these, because of low cost and availability, the chlorine compounds are preferred. Compounds containing a beta-chloroethyl group are preferred, because they are extremely eifective in small quantities and give highly desirable results. Beta,beta'-dichloroethyl ether is particularly preferred, because of its low cost, ready availability, and the outstanding results obtained through its use.

Propanol 2 gives excellent results, although larger amounts are required than certain of the chlorinated ethers to produce the desired effect.

In certain cases highly desirable results are obtained through a combination of anti-softening agents, as, for example, propanol-2 in combination with beta,beta'-dichloroethyl ether Other preferred organic compounds of this group are acetone, ethylene chlorohydrin, 1,3- glycerol dichlorohydrin, tertiary butyl alcohol, cyclohexanol, alpha, beta-dichloroethyl ethyl ether, and beta,beta-dihydroxyether. Polyhalogenated ethers, alcohols and ketones can also be employed to advantage.

In the use of said water soluble, neutral, aliphatic, oxygenated, organic compounds, the range of 0.01% to 4% by weight of developing composition, depending upon whether more or less of the sulfite and less or more of the inorganic alkali are utilized, constitutes a useful range, while the range of 0.015% to 3% is preferred, and. 0.02% to 2.5% constitutes an opti mum range.

Sodium tetra phosphate is advantageously added to the water, before the addition of the other chemicals, as a water softening agent.

The following composition produces an ideal developing solution in accordance with the invention:

Example No. 1

Sodium tetra phosphate grams 5 Monomethyl para aminophenol sulfate rams 10 Sodium sulfite do 180 Hydroquinone do 20 Sodium carbonate do 120 Ammonium bromide d.o 2 'Iriethanolamine cc l5 Beta,beta'-dichloroethyl ether -cc 1 Water to make one gallon of solution.

The triethanolamine and beta,beta'-dichlorodiethyl ether are advantageously dissolved in one another, and added to the aqueous solution of the other chemicals. The mixture is shaken, and is then ready for use.

The resulting developing solution represents a goal long sought in the photographic industry. It provides an average of second processing at 68 F., fine grain, normal contrast, extremely good gradation, excellent shadow detail, long life solution, low cost, excellent protection for the emulsion surface, ready availability of the chemicals, and complete and easy control during process of development.

Other typical compositions in accordance with the invention, each affording approximately 90 second action at 68 F., follow:

Example No. 2

Sodium tetra phosphate grams 5 Mono-methyl para aminophenol sulfate rams 8 Sodium sulfite do 200 I-Iydroquinone do 20 Potassium carbonate ..do.. Monoethanolamine cc 20 Potassium bromide grams 1.8

Ethylene chlorohydrin cc..- 5

x 3 Sodium tetra phosphate grams 4 Mono-methyl para aminophenol sulfate grams- 10 Sodium sulfite do 180 Hydroquinone do 2.0 Ammonium bromide do 1 Sodium carbonate do 140 'lriethanolamine cc 20 Beta-beta-.dichloroethy1 ether cc 1 Propanol-Z cc 20 -Benzo-triazole grain Ex mpl o 4 Sodium tetra phosphate grams 5 Monoemethyl para am'inophenol sulfate grams 8 Sodium sulfite do1 200 Chlorohyd-roquinone do 25 Potassium metaborate do 160 Sodium bromide do 2 'Diethanolamine -cc- 24 Acetone oc 30 Er mple N 5 Sodium tetra phosphate gr ams 5 Mono-methyl para aminophenol sulfite.

I grams- Sodium sulfite do 220 Toluhydroquinone "do-" 16 Potassium bromide 'do 2.5 Morpholine 'ce 10 Sodium carbonate grams 120 Glycerol cc 10 Beta-1 9 .18,edihydroxyethyl other cc 10 E'azample N o. 6

Sodium tetra phosphate grams 4 Mono-methyl para aminophenol sulfate grams 12 Hydroquinone do 16 Sodium sulfite clo 140 'Tri sodium phosphate do 100 Potassium bromide do 2 Triethanolamine ec 20 Propanol-2 oc 10 he as t i nven n s he e d cr b in d t il with re pect to s v ra spe ifi e d ment thereo it is t b ders o t a riou changes may be made therein and that various ther mbodiments may b r a ed on t basis oi the teaoh nes her o by os sk ed n tho art, Wi h u d pa ti rom h pr tec iv s op o he io lowine cl ms I claim;

A photoe aphie de lopin o posi n. oo taining an organic silver halide developer; sodium car n te; t oth no am ne; mm nium romide; and beta-beta?dichloroethyl ether.

Sodium tetra phosphate grams 5 Monomethyi para aminophenol sulfate grams 10 Sodium sulfite do 180 Hydroquinone d0 20 odium carbonate do1 Ammonium bromide do 2 Triethanolamine cc 15 Beta b ta'=dioh roethy1 eth r "sun-cc" 1 Water to make one gallon of solution.

LEONARD A. ROBBINS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 333,488 Williams 1 Dec. 11, 1906 2,017,167 Russell .Oct. 15, 1935 2,113,312 Vittum Apr. 5, 1938 2,124,608 Christensen July 26, 1938 2,172,216 Miller Sept. 5, 1939 2,191,037 Mannes 1, 1 Feb. 20, 1940 2,333,821 Salo Nov. 9, 1943 2,339,309 Veber Jan. 18, 1944 2,356,477 Stand Aug. 22, 1944 371,740 Bearing Mar. 20, 1945 2,374,921 Bunting May 1, 1945 2,378,203 Fallesen June 12, 1945 2,394,600 Fallesen Feb. 12, 1946 2, 07,114 McQueen 1- ,.1 May 9, 1 5 2,553, 98 Duerr 11 May 15, 1951 FOREIGN PATENTS Number Country Date 430,916 Great Britain June 27, 1935 471,922 Great Britain Sept. 13, 1937 512,060 Great Britain Aug. 29, 1939 520,753 Great Britain May 2, 1940 535,021 Great Britain Mar. 26, 1941 571,389 Great Britain Aug. 22, 1945 117,992 Australia Jan. 4, 1944 OTHER REFERENCES Millerioux A Rational Formula for a Metol- Hydroquinone Developer, Monthly Abstract Bulletin, Eastman Kodak Co. March 1938, page 122.

Morgan and Lester, Photo Lab Index 8th (1946), page 09, Sect. 13. 

1. A PHOTOGRAPHIC DEVELOPING COMPOSITION, CONTAINING AN ORGANIC SILVER HALIDE DEVELOPER; SODIUM CARBONATE; TRIETHANOLAMINE; AMMONIUM BROMIDE; AND BETA-BETA''-DICHLOROETHYL ETHER. 